REGULATION OF PERCHLORATE AT LOW LEVELS IN DRINKING WATER: A HIGH STAKES DECISION

In the mid to late 1990s, perchlorate was first detected in water supply systems in California, Nevada, Arizona and elsewhere.

Since then, the Perchlorate Study Group (eight aerospace, defense and chemical companies) has been working with the U.S. Environmental Protection Agency (U.S. EPA), the Department of Defense, NASA, state governments, water purveyors and other business organizations to: 1) increase scientific and medical understanding of perchlorate's effects on the body, and 2) assess whether there is a level of perchlorate in drinking water that poses a risk to human health.

It is now known that perchlorate's direct effects on the human body are limited to the thyroid gland, and only if ingested at very high levels (above 14,000 ppb) for a prolonged period of time (typically years). Peer-reviewed scientific and medical studies conducted over a broad range of exposure levels in humans show that perchlorate in drinking water below 245 parts per billion (ppb) has no measurable effect on human health. Levels below 14,000 ppb do inhibit the body's ability to absorb iodine, but even this is not an adverse health effect. These findings, together with new research completed in 2004, provide reason to believe that low levels of perchlorate (even levels higher than any found in drinking water) also have no measurable effect on pregnant women or fetuses.

PERCHLORATE EXPOSURE IN DRINKING WATER BELOW 245 PARTS PER BILLION
HAS NO MEASURABLE EFFECT ON HUMAN HEALTH.

The Perchlorate Study Group is committed to ensuring that the best available science is used in both the public debate and in setting regulatory standards.